MHT CET202611 April 2026Morning ShiftPhysicsAtomic PhysicsActual
The kinetic energy of the electron in an orbit of radius r in hydrogen atom is proportional to ( e = electronic charge)
Options
- Ae^2 2r^2
- Be^2 r
- Ce^2 2r
- De^2 r^2
Correct answer
C. e^2 2r
Step-by-step solution
The electrostatic force between the electron and the nucleus provides the necessary centripetal force for the circular orbit. mv^2 r = 1 4 ₀ e^2 r^2 mv^2 = 1 4 ₀ e^2 r Kinetic energy, K = 1 2 mv^2 = 1 4 ₀ e^2 2r In CGS units, 1 4 ₀ = 1 , so K = e^2 2r . Answer: e^2 2r